Apple has been accused of infringing a patent that is claimed to cover the design of its popular iTunes music jukebox software.

Earlier this month, US-based Contois Music and Technology filed a lawsuit with the Vermont District Court alleging that iTunes infringes US patent number 5,864,868, according to an AppleInsider report. The patent was filed by Contois co-founder Dave Contois in February 1996 and granted in January 1999.

The company claims it informed Apple about the alleged infringement in September 2004, though it maintains the Mac maker knew about its patent back in January 2003. On that basis, it says Apple's infringement is wilful, and has asked the Court to ban iTunes' distribution and for a jury to grant it unspecified damages for the trouble it maintains Apple has caused it.

Contois' patent describes a "computer control system and user interface for media playing devices" in which "the system provides a user interface for allowing a user access to media pieces stored in a media database".

The patent is clearly intended to cover the use of a computer to control an external music instrument, providing it with data to play back the tune selected. The patent describes a user interface that allows someone to choose the tune from a variety of categories, such as artist, genre, title and so on.

It's the latter aspect, Contois claims, that iTunes has aped. The family owned company maintains it demonstrated such a system in 1995 and 1996, where it was seen by people who were either contemporary employees of Apple or would go on to join the Mac maker. Either way, they took inspiration from Contois' demo, the plaintiff claims.

iTunes started life as SoundJam, a music playback application published in 1999 by Casady & Greene. Apple acquired the program and hired its developer in 2000, and relaunched it as iTunes in 2001.

Contois is focusing on that launch. The plaintiff cites 19 instances where iTunes' UI matches elements described in its patent, including its track search and selection system, and the ability to transfer songs to a portable device.

Apple has already found itself in hot water over iTunes. It is currently engaged in a legal spat with Apple Corporation, the Beatles' recording company, over the alleged transgression of an agreement the two firms signed in the 1990s detailing the markets the Mac maker was allowed to take its brand into. Music, Apple Corp. claims, was not one of them, though that's just where iTunes has taken Apple Computer.

Separately, it's being sued by Hong Kong-based Pat-rights which claims ownership of key elements of Apple's FairPlay DRM system. The iPod is claimed to infringe Chicago-based Advanced Audio Devices' patent for a "a music jukebox which is configured for storing a music library therein"

And a French consumer group is suing Apple on the grounds that it believes the limitation on tracks downloaded from the iTunes Music Store that they may only be played with the iTunes application or an iPod but not any other MP3 player is a violation of European Union competition law. A similar complaint has been laid before the California District Court. ®